Chickpea seed proteins: Modification during germination

Changes in the proteins of chickpea during a 12-day germination period are reported using techniques of gel filtration, DEAE-cellulose chromatography, polyacrylamide gel (PAG) electrophoresis and ultracentrifugation. In the ultracentrifuge, the total proteins of dormant seeds resolve into 3 components which have the sedimentation coefficients of 2.2 S, 6.9 S and 10.3 S respectively. On germination, the presence of fractions of lower sedimentation coefficient indicates possible degradation of these components; in the early stages, the degradation rate of the 7 S fraction is higher, while the 10 S fraction is broken down faster in the later stages. Gel filtration experiments indicate the possibility of degradation of high polymer into intermediary products. Increase in the relative mobility of protein components on PAG and elution constant on DEAE-cellulose chromatographs indicates an increase in the net negative charge of the protein fractions. The accumulation of subunits of the proteins is negligible during the germination period.     

Seed glycoproteins of Lupinus angustifolius

The seed globulins of Lupinus angustifolius are glycoproteins containing 1.4–1.9% (α-conglutin), 2.8–6.4 % (β-conglutin) and 1.2–3.8% (γ-conglutin) carbohydrate. The highest values were obtained after acid hydrolysis and determination by phenol—H₂SO₄, (α, γ-conglutins) or by methanolysis and sugar determination by GLC (β-conglutin). TCA denaturation of β- and γ-conglutins was necessary to remove adsorbed galactomannans before determination of glycoprotein carbohydrates. All 3 conglutins contained mannose, galactose and glucosamine, though the ratio of mannose to galactose, and to a lesser extent neutral sugars to hexosamine varied. Small amounts of fucose were found associated only with γ-conglutin.     

The horseradish tree,Moringa pterygosperma (Moringaceae)—A boon to Arid Lands?

The horseradish tree (Moringa pterygosperma,) is being introduced into drought-ridden lands to augment the local food and fodder supply. The tree grows up to 5 m per year. The foliage is high in calcium and has half the oxalates of amaranth. Seeds yield edible oil and the seed meal is used as fertilizer and as a coagulant to clarify turbid water. The philanthropic center, ECHO (Educational Concerns for Hunger Organization), North Fort Myers, Florida, receives many requests for seeds. A missionary in Mali wrote: “The seeds you sent arrived during the worst year of 14 years of dry weather. Only the moringa survived, and they have flourished. ”Another seed shipment resulted, after harvesting a crop, in 25 000 trees being planted by university students and faculty, around laborers’ houses in Maranhao, Brazil. The tree is not limited to tropical lowlands, but thrives at elevations of 800-1200 m in protected mountain areas of southern Mexico. The long-range effects of ingesting various parts of the tree as food or folkmedicine need study. Attention should be given to horticultural improvement, perhaps through hybridization with one or more related species now being compared with M. pterygosperma in India and Africa. ХРеНовое дерево, Moringa pterygosperma F. Gaertn. (Moringaceae), Дар сыхим землям. Хреновое дерево, Moringa pterygosperma, вводится в бездождивые землии чтоб умножить местное снабжение пищи и корма. Дерево растет до 5 метров в год. Листья содержат много кальцию и половину щавелев по сравнени#x044E; с амарантом. Семя дают съедобное масло и семеная мука употребляется как одобрение и как коагулант для очищение мутной воды. Филантропический цэнтэр ECHO (Educational Concern for Hunger Organization, North Fort Myers, Florida) полужает мното просьб чтоб получить семя. Один миссионер из Мали писал “Семя которые вы послали, прибыли в самый сухой год за 14 лет сухой погоды. Только моринга пережила и цвела. Другая отправка семен была совершена после получения урожая и 25000 деревьев были посажены студентами и учителями около домов рабочих в Маранхау, Брразилия. Это дерево не ограаничевается тропическим климатом и преуспевает на уровне 800 до 1200 метров в защищенных горных местах южной Мексики.     

葡萄籽油和饼粕的化学成分及特性研究

本文报道了葡萄耔油和饼粕的化学组成及特性。经测定,葡萄籽中粗蛋白、脂肪和纤维素的含量分别为8.4%、15.0%和37.2%;葡萄籽油中,不饱和脂肪酸为89.6%,其中亚油酸占72—76%,碘值、皂化值和酸值分别为138.3、191.5和1.68。我们还对重要矿物元素Ca、Mg和K的含量进行了测定。在葡萄酿酒后的下脚料中,葡萄籽占20—26%,对其进行二次深加工,不仅可以减少环境污染,还可以增加社会经济效益。     

Phytochrome-mediated changes in the ATP content of Kalanchoë blossfeldiana seeds

One short red (R) irradiation increases the ATP content of Kalanchoë blossfeldiana Poelln. cv Feuerblüte seeds before onset of germination. Phytochrome control is demonstrated by the full R/far-red light (FR) reversibility of the effect in water imbibed seeds. In seeds imbibed in the presence of gibberellin A₃ (GA₃, one short R exposure already increases the ATP content when given 2h after start of imbibition, showing phytochrome control at the energy-metabolic level when one R pulse cannot yet induce germination. After longer imbibition periods in the presence of GA₃, one short FR irradiation also increases the ATP content of ungerminated Kalanchoë seeds. The time course of the ATP levels after a R or FR germination inducing irradiation shows an initial increase that clearly preceeds germination. A second increase starts about 15 h after irradiation and is most probably the consequence of the germination itself. The results suggest that, in Kalanchoë seeds, the increase in ATP levels, induced by irradiation(s) and preceding germination, is a phytochrome-mediated process, supplying energy, required for germination.     

Pea dehydrins: identification,characterisation and expression

An antiserum raised against dehydrin from maize (Zea mays) recognised several polypeptides in extracts of pea (Pisum sativum) cotyledons. A cDNA expression library was prepared from mRNA of developing cotyledons, screened with the antiserum and positive clones were purified and characterised. The nucleotide sequence of one such clone, pPsB12, contained an open reading frame which would encode a polypeptide with regions of significant amino acid sequence similarity to dehydrins from other plant species.The deduced amino acid sequence of the pea dehydrin encoded by B12 is 197 amino acids in length, has a high glycine content (25.9%), lacks tryptophan and is highly hydrophilic. The polypeptide has an estimated molecular mass of 20.4 kDa and pI=6.4. An in vitro synthesised product from the clone comigrates with one of the in vivo proteins recognised by the antiserum.A comparison of the pea dehydrin sequence with sequences from other species revealed conserved amino acid regions: an N-terminal DEYGNP and a lysine-rich block (KIKEKLPG), both of which are present in two copies. Unexpectedly, pea dehydrin lacks a stretch of serine residues which is conserved in other dehydrins.B12 mRNA and dehydrin proteins accumulated in dehydration-stressed seedlings, associated with elevated levels of endogenous abscisic acid (ABA). Applied ABA induced expression of dehydrins in unstressed seedlings. Dehydrin expression was rapidly reversed when seedlings were removed from the stress or from treatment with ABA and placed in water.During pea cotyledon development, dehydrin mRNA and proteins accumulated in mid to late embryogenesis. Dehydrin proteins were some of the most actively synthesised at about the time of maximum fresh weight and represent about 2% of protein in mature cotyledons.     

Differential effect of temperature on mitrochondrial activity in shoots from freshly harvested and moderately aged kernels of maize (Zea mays L.)

This paper reports on a study of mitochondrial activity in etiolated shoots of freshly harvested and moderately aged kernels of maize. Activity was investigated after incubation at a favourable temperature (25°C), sub-optimal temperature (13°C) and after a heat shock (46°C for 2h). Although impaired mitochondrial activity in shoots from moderately aged maize kernels was not detected at 25°C, deficiencies became evident under low temperature stress (13°C). State 3 oxygen uptake, cyanide-insensitive oxygen uptake and cytochrome oxidase activity were lower in mitochondria from these shoots at 13°C than in mitochondria from shoots of freshly harvested kernels at this temperature. After a heat shock, cyanide-insensitive oxygen uptake was higher, and cytochrome oxidase activity lower, in shoots of aged kernels than in shoots of fresh kernels. No significant differences in ADP: O ratio or succinate dehydrogenase activity occurred between mitochondria from shoots of the two seed lots in any of the temperature treatments.     

花生种子萌发早期胚轴DNA合成与种子活力的关系

随着花生种子萌发率和活力指数的下降,胚轴DNA开始合成的时间推迟,其合成水平也降低。但DNA合成都是先于吸胀的12h(高活力胚)或18h(低活力胚)出现一个峰,然后再持续上升。腐胺预处理明显地促进老化胚轴萌发早期(12～2dh)的DNA合成。钙离子预处理则有一定抑制作用,但两种预处理均能提高种子的活力指数,并能促进吸胀30h以后的DNA合成。     

Development of a technique to study seedling emergence in response to moisture deficit in the field —The seed bed environment*

The ability of crops of sorghum (Sorghum bicolor (L.) Moench) to establish in farmers' fields depends largely on its capacity to germinate and emerge under limited soil moisture conditions. Studies on germination under moisture stress have been previously conducted using osmotic media which do not wholly reproduce the conditions of the seed bed in the field. Hence the need for a field screening technique. A line source irrigation system was used to provide five moisture regimes ranging from -0.08 MPa to -0.92 MPa. The drying rate of the soil and the soil temperature depended largely on incident radiation, and the relationship between the moisture content and daily soil temperature and daily radiation was consistant. Total porosity of the seed bed, derived from bulk density measurements and particle density ranged from 43.8% to 45.3%, which would allow sufficient aeration when as in the experiments conducted here, water content was low (> 0.14 g/g). Under these seed bed conditions the pattern of response of emergence to the moisture gradient was linear or curvilinear. Genotypic differences existed for emergence and its response to water level. The field method developed is useful for identifying genotypes able to germinate and emerge under conditions of low seed bed moisture.     

Soaking injury and its reversal with polyethylene glycol in relation to respiratory metabolism in high and low vigor soybean seeds

Germination and growth of unaged (high vigor) and accelerated aged (41°C and 100% RH for 4 days; low vigor) soybean [ Glycine max (L.) Merr. cv. Essex] seeds were severely reduced by soaking the seeds under water at 25°C during the first 1 to 8 h of imbibition. Soaking in 30% polyethylene glycol (PEG) did not injure high vigor seeds and improved the performance of low vigor seeds. Soaking in water increased subsequent RQ values and acetaldehyde and ethanol levels. In high vigor seeds, the increase in RQ lasted only 1 h after transfer to aerobic conditions, whereas in low vigor seeds the increase persisted into the second h. Increases in ethanol and acetaldehyde after soaking were more pronounced in low than in high vigor seeds. The data indicate that relatively short periods under water can cause water uptake injury to imbibing soybean seeds and that this injury can be avoided by osmotically reducing the initial rate of water uptake. Seeds whose vigor has declined during accelerated aging show an additional injury which increases with soaking duration and involves alterations in respiratory metabolism including accumulation of acetaldehyde and ethanol to high, and possibly toxic, levels during imbibition.